Glass Cockpit

The part of the project I am working on now is to make an EFIS (Electronic Flight Instrument System). This consists of 4 units, a display, a display computer, an ADAHRS (Air Data, Attitude, and Heading Reference System), and a magnetic compass. They are connected by a bus. I will be able to attach 2 buses to the display computer for redundancy. A diagram of the system is below.

...........      ...........       ...........       ...........
.         .      . Display .       .         .       .         .
. Display .<....>.         .       . ADAHRS  .       . Compass .
.         .      . Comp    .       .         .       .         .
...........      ...........       ...........       ...........
                   .    .             .                  .
                   .    .             .                  .
  CAN Bus A        .    .             .                  .
........................o.............o..................o......
                   .
...................o..................o..................o......
  CAN Bus B                           .                  .
                                      .                  .
                                      .                  .
                                   ...........       ...........
                                   .         .       .         .
                                   . ADAHRS  .       . Compass .
                                   .         .       .         .
                                   ...........       ...........
                                                           

Display

The display is mounted on the instrument panel and will also have buttons for input to the display computer. I got a small 5" monitor off of the mp3car site. This unit has a separate power supply box so is kind of complicated. It also has a touchscreen, which I probably won't use.

Display Computer

The display computer drives the display and also connects to the busses to read the data supplied by the sensor boxes.

• ARM CPU for low power
• USB port
• Linux OS
• Dual CAN controllers and connectors
• 12V Power supply

Details

ADAHRS

The air data, attitude, heading reference system senses and encodes onto the bus the following data:

• Pitch, Pitch Rate, Pitch Acceleration
• Roll, Roll Rate, Roll Acceleration
• Yaw, Yaw Rate, Yaw Acceleration
• Total air pressure and Temperature
• Static air pressure and Temperature
• Angle of attack air pressure and Temperature

Details

Compass

This one is simple, provide 3-axis magnetic field strength sensor data so that magnetic heading can be calculated. Encodes the data onto the bus.

Details

Tools

• Schematics - gschem
• Circuit Board Layout - pcb
• Gerber Viewer - gerbv
• Soldering
• USBTiny for AVR firmware programming
• Oscilloscope - Nano V2
• Embedded Software
• Angstrom distribution for display processor
• GCC for both display computer and 8-bit AVR's
• GNU Make and qmake for project builds
• git and Github for software configuration management
• Qt for graphics display
• avrdude to download firmware to boards